Describe the bug
After upgrading A2A.AspNetCore from 0.1.0-preview.2 to 0.3.1-preview, the project fails to build when using Microsoft.SemanticKernel.Agents.A2A.
The error indicates that A2AClient is missing because the package Microsoft.SemanticKernel.Agents.A2A is still referencing A2A version 0.1.0.0 and has not been updated to align with the newer A2A.AspNetCore dependency.

Error message:

A2AClientExtensions.cs(49, 16): [CS0012] The type 'A2AClient' is defined in an assembly that is not referenced.
You must add a reference to assembly 'A2A, Version=0.1.0.0, Culture=neutral, PublicKeyToken=null'.

To Reproduce
Steps to reproduce the behavior:

1. Create a new project referencing Microsoft.SemanticKernel.Agents.A2A and A2A.AspNetCore version 0.3.1-preview.
2. Build the project.
3. Observe the compile-time error about A2AClient.

Expected behavior
Microsoft.SemanticKernel.Agents.A2A should reference the updated A2A dependency (0.3.1-preview) so that projects can build successfully with the latest preview.

Screenshots

Platform

• Language: C#
• Source: NuGet
• Microsoft.SemanticKernel.Agents.A2A (latest)
• A2A.AspNetCore (0.3.1-preview)
• IDE: Jetbrains Rider
• OS: Windows 11

Additional context
This seems to be caused by a version mismatch: Microsoft.SemanticKernel.Agents.A2A is still locked to A2A 0.1.0.0 instead of the latest preview (0.3.1-preview). Updating the dependency would resolve the issue.